1. Field of Invention
This invention relates to the technology for authenticating computers, measuring devices and other devices having serial numbers or other types of inherent device numbers.
2. Description of the Related Art
Various methods are used for upgrading software installed in a computer or firmware built in a measuring device.
If the software or firmware is stored in EPROM or similar devices, replacement of the corresponding part is the first method. If this method is adopted, measuring devices or the like must be collected from the user to parts replacement contractors or manufacturer because parts replacement is hard for users. Therefore the labor cost for upgrading is large.
Next, the floppy disk or the like can be used for upgrading. That is, software or firmware is stored in a nonvolatile memory inside the measuring device or the like. A recording medium such as a floppy disk on which upgrading software is recorded is handed over to the user. As a last step, the user uses the recording medium such as a floppy disk to upgrade software or the like.
This method contains the following disadvantage. Even if upgrading software includes an onerous part, there is no method to prevent the upgrading floppy disk obtained by a certain user from being used by another user for illegal upgrading. Next, if two or more kinds of upgrading software are recorded in the upgrading floppy disk according to the internal configuration of the same model of the measuring device or the like, the user may execute a wrong kind of upgrading software.
These disadvantages are common for download of upgrading software from an external computer through an interface and download via Internet.
These disadvantages originate from lack of authentication of the measuring device or the like to be upgraded.
That is, if the upgraded measuring device or the like is known to the manufacturer or the like, the user having used the upgrading floppy disk, even if the same floppy disk is used by two or more users, can be billed later.
Moreover, if the upgraded measuring device or the like is known to the manufacturer or the like, an upgrading program suitable for the model of the measuring device can be provided. Thus wrong upgrading can be avoided.